Backyard Aquaponics
A place to discuss aquaponics

Hi All

I apologise in advance for all my painful newbie questions

I was thinking of using an old spa as my fish tank but according to my calculations it is only about 800 litre capacity. I was also thinking of using blue barrel halves (100L/half) as beds. (read budget setup) How beds would be best for 800L? If I sink the spa into the ground with beds above is it likely I would need to use a sump?

Contemplating trying silver perch, can anyone advise how many I could aim for in 800L?

Or if my lack of knowledge is glaringly obvious, and that is the dumbest idea ever, please tell me if Id be better off throwing the spa away and use multiple tanks/IBC's to get a bigger capacity???

Dont want to go too big for a first effort, but dont want a setup with only two fish in it

I also have the corresponding spa pump - unfortunately I have no specs for it but presume t is heavy duty as far as pumps go - it is useable in this scenario or would it be way too big? If so is there anyway to restrict it? Any ideas on cost of a new suitable pump as a comparison would be great

Lastly just wondered if there was any reason pvc pipe seems to be used over flexible hosing?

Thanks

hey username.

look through the members systems and you will see all different types of fish tanks... from fridges to aquariums.. and 1/2 barrel growbeds are very common.. the biggest argument about them seems to be to cut them across or lengthways..

the only advice i would dare give (as newbie too) would be careful of what was in the drums and the chlorine in the spa..

i seem to see the whole "backyard" ap principle is to use whatever is at hand..

good luck!!!

thanks for the advice aLostHippy

The drums are ex food storage and cheap at about $20 a drum. The spa I have on hand, which makes it a lot more tempting to give it a try without spending thousands on a a shiny new setup.

i think there is more enjoyment in gathering bits and pieces and tinkering till it works...than just have it all made up for you..


but if i had the cash i would probably think the other way..

i have an ibc and a couple of drums and sloooooowly getting enough together... but i keep changing from using a sump to having the gb higher than the fish...

but it is all fun!!..... well it looks like fun....maybee.....

Username... my first system was a 700-800L tank... pumping to half blue barrels, loop siphons draining (by gravity) back to the tank.... works like a charm...

Only constraint with a small tank... is temperature tends to fluctuate much more... and the amount of fish you can stock is correspondingly smaller than a larger system...

But it's not a bad way to start... until you build you second bigger system... and you will...

Username

I think you will find the spa pump overpowered (can't believe I said that ) for your application. The only way to operate it would be on a timer and I would worry about a 10amp burning out the contacts in time ie you may need a 15amp one. Check out F&F's thread he is using a very large pump but only intermittently.

thanks - will do.

F&F's thread was 109 pages long

It was inspirational to see the progress from day one right through to successful harvests.

Reading through a few of the big long threads is something I have taken to suggesting to the new people asking where to start (along with telling them to read the useful info and basic info sections.) The big long threads can often answer many of the little questions that come up with the backing story of what can go wrong if you try things a different way. It also helps to show the progress from design to building to re-design to cycling and getting fish to plants to pests and bugs to harvest and system expansion. And Algae, to shade cloth to covers to stop fish from jumping out and so on.

I've been noticing lots of spas and hot tubs on free cycle and craigs list lately. I would check to make sure there isn't any galvanized or copper plumbing to contact the system water involved in using the spa. And otherwise it should make a fine starter fish tank.

As far as the blue barrels. I had decided that they might not be so cost effective (especially if you cut them lengthwise) since you then have to pay for more plumbing parts to hook them up and supports to hold them without buldging. So I used pond liner and lumber to make my grow beds and figure it came out to about the same price and actually takes up less space in my yard.

I'm rather partial to CHIFT PIST systems now since I get weary of cleaning my pump trap all the time. My future system will probably be CHIFT PIST (or perhaps I should say Pump In Sump Bed since I would probably fill the "sump" with gravel in our high water table area.)

But if you choose to sink the spa into the ground some and place the barrels above the height of the fish tank, I would recommend cutting the barrels around the middle so you have round grow beds that won't buldge when full of water and gravel. Remember that the water level in the spa will fluctuate if you don't do a system with a sump. If you manage 800 l of grow beds, then you could probably have about 24 kg of fish at final grow out size (once the system is well cycled.) I don't know the normal grown out size of a silver but if it is a kg, then you could have over 20 fish. It is generally good to start with somewhat lower stocking density at first though. Luckily smaller fish help in this starting small sort of thing and hopefully your skills and bio-filter will grow as they do.

Good Luck, keep reading!

That's an average price for blue barrels yes.
you should try to match at a minimum yes.
Ideal is twice that, so 8 full barrels, 4 half barrels.

With the oversized pump problem, you can use a header tank with different feeder lines coming from it. Make at least 1 return go back to your "tank," and put valves on them. You'll have to play with the valves to get the flow in to balance the flow out.

Some will point out that this is very inefficient from a power consumption viewpoint, but it's probably cheapest in that you're not buying a new pump.

no, it's efficient. You're moving more water than you need to, but it's not wasting power.
it will aid in circulation and aeration, while costing you no more.

I meant inefficient in power consumption when compared to a smaller pump that pumps the right flow at the given head. A larger pump will use more electricity (at least within similar design families, etc)

Imho I would agree with KP for that pump, efficiency curve is probably quite high (in terms of head). Straight up to a header, as you suggested Tamo, put it on a timer if the headers big enough; would probably do that anyway.
Any specs on the pump Username?

BTW if you do a search, Pump with Food & Fish as the member it might save some time (not as interesting though )